difficult one as there is no point spending all that on the CD player if you dont have an amp to listen to it on.
I would firstly pick up a decent amp, £150 to £200 will get you a very capable amp that would have cost around the £500 when released. deends what sound your into. if you like it rich and a little warmer go towards Arcam, if your pref is detailed and taut head over to the cyrus and audiolab camps, the roksan and naim offer a little of both, huge slam and detail and the sound is so lively, yet keeps a nice rich sound, you will pay more though.
As for what mods to do 1st and who to do them, these guys adfinni linked to seem pretty good, but only see, to offer the £255 mods with the superclock mod on top of that available.
http://www.sercal-electronics.co.uk/modules.php?op=modload&name=News&file=article&sid=8
It may be worth you emailing them and asking if they could just do a few of the mods, maybe just the superclock 2 mod first, when you have the funds do the rest.
Alternativly, ask around, see if any local hi-fi shop would be will to fit a superclock2 (which you can pick up off the bay for £60)
1 final thing, dont forgot the cables, for interconnects I cant reccomend MArk Grant Cables enough, fantastic quality and price, you can get them made exactly to size as well. Speaker cables, depends on what £ you have left and how much cable you use. I swear by Chord Rumour 2, but it is around £10 a metre. Vandamme blue is supposed to be very highly regarded and is only around £2.50 a metre