If it was me and I knew I'd be upgrading later on, I'd concentrate on one bit now. Id keep the amp, buy some decent 100-150 quid speakers (royds, tannoy 609, ruark sceptre, etc - are you limited to standmounts?) And then look for a nice TT and cart with the rest.
A rega p3 or so and 2m red woulbr new enough and simple enough to not be a problem
The next update I'd go big on the amp or speakers, depending on how I felt.