Go for the T630 at that kinda price range, you will only notice it's slow if you text very fast. With me i've finished the whole text before the first word fully pops up. The k700i is worth it if you can afford that much though. I had to shell out for mine up front on PAYG
There are also rumours of a K710i or something to that affect which will have a mmc card slot. The mp3 player is very limited with the amount of space it has on board.