Anyhow you will have to make some concessions. Having a Dutch rating of about 1800 myself it is a bit arrogant of me to advise you, but here I go.
First problem to tackle: the Sicilian. If the Bb5 and c3 systems are not to your taste, only the Open Sicilian remains. Remember one thing: it is impossible to prove an advantage (especially against the Najdorf and Svesjnikov), so don't waste time trying. The good news of course is, that the asymmetrical structures allow both sides (including you) to play for a win. As you can't keep track with the latest developments, chose lines, which are less time-consuming. More good news is, that White has several options against every sub-system.
Svesjnikov: 7.Nd5.
Najdorf: either 6.f4 e5 7.Nf3, 6.Be2 e5 7.Nb3 or 6.Be3 (after e5 both 7.Nb3 and 7.Nf3 are interesting, but 6...Ng4 might be a problem). If Black plays 6...e6, then
Najdorf/Scheveningen: 5...a6 6.Be2 e6 7.0-0 Be7 8.Be3 0-0 9.f4. I especially like a plan suggested by Gallagher: Qd1-e1-g3, Kh1, Bf3, Rfe1, Rad1 and the sac Nd5!? if possible.
Scheveningen: as I don't like 6.Be2 Nc6 7.Be3 Be7 8.0-0 0-0 9.f4 e5 too much (Willempie will disagree), either the Keres Attack 6.g4 (h6 7.g5 is out of fashion, maybe it is time for a revival) or 6.Be3 Be7 (a6 7.Be2; Nc6 evt. 7.Bc4 if you like the Sozin) 7.f4 Nc6 8.Qf3 as 8.Bc4 is an inferior Sozin now: 0-0 9.0-0 Nxd4 10.Bxd4 e5!
Sozin: if you think the Richter-Rauser too much (for the moment?) and don't want to allow the Boleslavsky 6.Be2 e5 7.Nf3 h6, only the Sozin 6.Bc4 remains. After e6 you will only enter the dazzling Velimirovic if it suits you: 7.Be3 a6 (Be7 8.Bb3 0-0 9.0-0 Nxd4 10.Bxd4 a6 11.f4) 8.Bb3 Be7 (Na5 9.f4 or Bd7 9.Qe2 b5 10.0-0-0) 9.f4 Qc7 (Na5 10.Qf3 Nxb3 11.axb3 0-0 12.g4) 10.Qf3 0-0 11.0-0 or 11.f5. Alas 6.Bc4 Qb6 is OK these days. I used to recommend 7.Nxc6 bxc6 8.0-0 g6 9.Be3 and e6 9.Bf4, but I am not sure anymore. So maybe the Richter-Rauser after all, unless you find something against 6...Qb6.
Dragon: all those Dragoneers know everything about the Jugoslav Attack. So it will be 6.Be2 Bg7 7.0-0 0-0 8.Nb3 Nc6 9.Kh1, leaving the choice between 10.f4, 10.Be3 and 10.Bg5 open.
Accelerated Dragon: everything depends on 2...Nc6/4...g6 5.Be2 Bg7 6.Nb3 Nf6 7.Nc3 0-0 8.0-0 a5. According to my database this is good for White.
Paulsen/Kan/Taimanov: if Black plays 4...a6, then 5.Nc3 and 6.Be2 systems. An interesting option is the gambit 2...e6/4...a6 5.Nc3 Nf6 6.Be2 Bb4 7.0-0. Somewhat annoying is 2...e6/4...Nc6. After 5.Be2 Nf6 6.Nc3 d6 we have that insipid version of the Classical Scheveningen, which Willempie likes so much. After 5.Be3 Nf6 6.Nc3 Black has Bb4 and also after 6.Nd2 Black has done very well. So it has to be 6.Bd3.
Best might be 5.Ndb5 Nf6 (d6 6.c4 Nf6 7.N5c3 is another shortcut) 6.Bf4 (6.N1c3 d6 7.Bf4 e5 8.Bg5 is a transposition to the Bg5-Svesjnikov) e5 7.Bg5 and White might benefit from having the knight on b1.
Four Knights: 6.Nxc6 bxc6 7.e5.
Second problem to tackle: the Petrov. In Dutch magazine Schaaknieuws IM Van Delft recommends either the main lines or 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3 Nxc3 6.dxc3. That is interesting, if Black castles kingside. More solid is Be7 7.Bf4 Nc6 8.Qd2 h6 (Be6 9.Ng5 gets the pair of bishops) 9.0-0-0 Be6 followed by 10...Qd7 and 11...Bf6.
Ruy Lopez: buy yourself the recent book on the Worrall or play the Scotch.
French: 3.Nc3 as after Bb4 I like 4.e5 c5 5.a3 Bxc3+ 6.bxc3 Qc7 (Ne7 7.h4!?) 7.Qg4 Ne7 8.Bd3 (Geller). After 3...Nf6 either the Alekhine-Chatard 4.Bg5 Be7 5.e5 Be7 6.h4 or the Steinitz 4.e5.
Caro-Kann: If you chose the French Steinitz, you might consider 3.f3, as e6 4.Nc3 Nf6 5.e5 Nfd7 6.f4 transposes. Otherwise the Advance. After Bf5 you have the choice between Short's Variation, the ultra-sharp 4.Nc3 e6 5.g4 or the interesting 4.h4. Recently Goeller has presented some stuff on
http://www.kenilworthchessclub.org/games/java/2007/caro-adv-h4.htm Pirc: 4.Be3 Bg7 5.Qd2 c6 (0-0 6.0-0-0) 6.Bh6 or 4...c6 5.h3 and 6.g4 or 6.f4.
Robatsch etc: 4.Be3 c6 5.f4 and White can try to save the tempo x.h3.
Scandinavian: main lines.
Alekhine: Exchange 2.e5 Nd5 3.c4 Nb6 4.d4 d6 5.exd6, especially cxd6 6.Nc3 g6 7.Be3 Bg7 8.Rc1.
I have tried to recommend variations, which will probably not be refuted by some innovation from a remote country and quite easily can be substituted if necessary.
As Black the KID looks more economical to me than the Semi-Slav. For some reason the old-fashioned lines with ...Nbd7 are impopular these days. A pro is, that Black can avoid the Four Knights, the Sämisch and the Bg5-systems by employing the move-order 1.d4 Nf6 2.c4 d6 3.Nc3 Nbd7 4.e4 (4.g3 e5 5.Nf3 g6 6.Bg2 Bg7 7. 0-0 0-0 8.e4 exd4 following Gallagher's example) e5. After 5.Bg5 Black has Be7; after 5.f3 c6 6.Be3 Be7; after 5.Nge2 c6 6.f3 Be7 or 6.g3 g6.
So only the main line 4.e4 e5 5.Nf3 g6 6.Be2 Bg7 7.0-0 0-0 remains. 8.Re1 (8.Be3 Ng4) c6 9.Bf1 a5 10.Rb1 Ng4 is one try: 11.h3 exd4 12.Nxd4 Qb6 Portisch-Udovcic, Bled 1961, where 15...Ne5 16.Qd1 Be6 seems to improve.
If you like Tiger's Modern or the Pirc you might also consider 1.d4 (because of 1.e4 g6 2.d4 Bg7 3.c4 d6 4.Nc3 Nf6) g6, evt. answering the London etc. with ...f5, entering good versions of the Leningrad.
But iirc you prefer the Najdorf.
I hope this helps.