While not a "true" mod, I think my varible voltage Ovale V8 is very much worth a look in your category. It's small and yet packs the power in there. Oh yeah, it's also only $30 standalone, or $49 for the kit. (which is worth it IMO)
Here's some size comparisons.
Those pics are with a VaporKings Joye 510 atty @ 3Ω, and that's the black rubberized model I got from DV, but it comes in like 5 colors though.
Using a basic Acrylic tip and a Dichrotic Orange Trippy Tip. I've also used CE3 Clearos and regular cartos on it too.
