I pulled my 2007 Epi catalogue and the from that book, the Dot Studio and the G400 have the same pickups. The Dot Studio has the open coils. I measured my 2007 G400 using the patch cord/multi meter system, and found the pickups to be 8.21 Neck and 12.95 bridge, resistance. I would expect the open coils to be hotter. I also have a Sheraton II that is just a regular Dot with a lot more bling. That one has the stock epi pickups from 2001 and they are at 8.43 and 8.67. This of course is a solid block guitar so very little feedback. I like these pickups because it gives a kind of dirty mellow tone for the blues.
My ES335 has PAFs in it and they are in the 7.11 and 8.79 range. Again a centre block guitar not full hollow body.
What I am getting at is that if you like the tone of the stock pickups you would be looking at a set of Gibson 490/498 pickups or something aftermarket like that.
If you want a little mellower tone but still some bite, as Spudman said, I would go with a PAF or PAF clone.
That being said I hope you realize that if you do go with the pricier pickups you will not recoup that money if you sell. Also get wqx potted to keep the feedback down.
Another option is to change the pots and caps, which usually opens the stock pickups up a lot. On a Dot that would entail a lot of fishing and I am not sure I would tackle that one on my own. I have found by comparison that the newer off shore stock pickups are much better and fairly close to the originals.
The Blues is alright!
Guitars: 1968 Gibson SG, 2005 Gibson SG Standard, 2006 Gibson LP Classic Gold top, 2004 Epiphone Elitist LP Custom, 1996 Gibson Les Paul Standard. 2001 Epiphone Sheraton II, 2007 Epiphone G400.
Fender Strats: 1996 Fender 68 Reissue CIJ, 2008 Squier CV 50s, 2009 Squier CV 50s Tele Butterescotch Blonde
Amps: Blues Junior Special edition Jensen in Brown Tolex with Wheat front, 65 Deluxe Reverb reissue,1970 Sonax reverb by Traynor, Avatar Custom 2/12 Cabinet with Eminence Legend V1216 speakers,
2008 DSL100 Marshall Amp , Fender Super Champ XD,Fender Vibro Champ XD
Effects and Pedals: Fulltone Fulldrive II, Fulltone OCD, Fulltone Mini Deja Vibe, Fulltone Fat Boost, Dunlop Crybaby Wah, Boss DS1, Boss DD20 Giga Delay, Boss TU2 tuner, Boss BD2, Ibanez TS9 Tube screamer, Zoom 505. Radial tonebone hot british.