Want to Upgrade

I've got a 2010 Tacoma Standard Cab and I think it's about time to start considering an upgrade to the audio in it, which is terrible. This Tacoma is really just my little workhorse that I use on the weekends or when snow warrants the 4WD. It's not my daily driver. So, I don't want to go overboard with the audio, but I would like an upgrade. I do use the Tacoma to take my motorcycle to the track about 8 times/year, which tends to be long early morning/late night drives. I don't really want to cut too much or have to spend too much time modifying to truck to get something to fit right. I'd like to replace the existing speakers with something better and replace the head unit. Subs would be nice, but really not sure I want to give up the space. Thanks in advance for any suggestions!

**Oh yeah... considering these at first look: http://www.crutchfield.com/p_107DXI5250/Polk-Audio-DXi-5250.html?tp=105#customer-reviews-tab