Probably one other benchmark in skill level for twins is the ability to make successful deadstick landings without a lot of drama attached. This will give you the option of closing the throttle on the live engine if necessary rather than struggle with it and fall below Vmc while trying to get back to the runway. Also for a first twin heed the advice of others here and pick something that has a lower wing loading rather than something with a huge cool factor.
Remember that the ugliest plane that will taxi back to the pit area is superior to the very best being carried back in a trash bag.
ORIGINAL: Build-n-flyer-RCU
Ed's recommendations are right on the mark.
If you can handle a quick sport plane you should be able to fly any of these planes without any problems as long as both engines are running. And as long as you don't panic, getting the plane down in one piece with an engine out (on these twins) should not be a problem, but this is the tricky part.
Airplane and engine setup experience is probably just as important (if not more so) than flying experience. If the engines are reliable and you don't have deadsticks or throttle control problems, then the flying is easy.
For this reason I prefer the Twin Stick or Twin-Air. There is a good selection of very reliable 46 size engines (OS 46AX for example). From what I have seen the smaller engines used with the Twinstar or profile P-38 don't seem to be nearly as reliable.
Walt