Del Sol speaker advice

I'm trying to get an idea of what people think might be the best type of speakers to put into the rear pillars of a Del Sol.

I went and put infinity 6.5 inch component speakers into my doors (many thanks to the moderator for door panel removal info).

I'm looking to replace the rear ones now. I checked out the stock mounting brackets and tested my front ones prior to their installation in said brackets just for the sake of curiosity. It looks like I can fit just about any 6.5 back there with a drill and some patience - and still be able to cover them with the stock grills.

Does anybody have some suggestions? I'm thinking of just going with the theme and throwing some infinity coax or triax 6.5's back there. I'm going to be powering them all with a four channel amp, so I'm going to need speakers that are close to the 90 watt RMS of the ones in my front so I don't blow them.

I like the front ones just the way they are, and have a modest sub in the trunk (I like my music loud and rich, but don't particularly feel the need to annoy people three cars away). Unfortunately, compared to what I had in my old ride, it just sounds like the whole system is missing something, and I figure throwing two more 6.5's in there would do the trick.

Ideas?

Thanks in advance

don't bother with rear speakers