Go with which ever aircraft you feel comfortable in and can afford. I trained in a 152 and had no trouble. When I got my license I got checked out on a PA28 in under 2 hours and loved it, although it was more expensive.
The only real problem I had with a 152 was the lack of power, not so good considering I was flying around during hot and humid summer days... Also the seats are damn uncomfortable (I ended up logging 35+ hours sitting with the cowl plugs as a lumbar support!).
I found I tended to get much smoother landings in the PA28. The low wing makes for much more ground effect and the landing gear is not as rigid as the Cessna. My additional experience probably helped a bit too though.
I never found the lack of electric flaps a problem in the PA28, the feel of pulling up the big lever with one hand and letting the yoke pull forward in the other helped me get a better idea of what the aircraft wanted to naturally do. Personally I think i'd go for the manual lever now given the choice, especially after I experienced a flap servo failure during lessons!