Don't think EmuLoaded does low-res, I could be wrong tho.
MAMEWAH works with both AVGA & SlikStik, you might need to do some tweaking depending on how the inputs are mapped etc... Personally I use 368x240 for the layout, it looks great IMHO.
I'm not 100% sure which other FE's support the AVGA, so I'll leave it up to the other devs
