If you have A500+'s then you need to remove their batteries as soon as possible otherwise they will self destruct.
http://eab.abime.net/showthread.php?t=47185
I'd hold off buying a flicker fixer for the time being. Especially as in the UK your LCD TV will have RGB SCART and a built in flicker fixer.
Spend your money on the best accelerator you can afford. An Apollo 1240 upgraded to an 80MHz 1260 will set you back about £280
You probably want to buy a PCMCIA->CF adapter + CF card (~£10) to make it easy to get data between your PC and your Amiga.
I wouldn't recommend buying a CD. Just put your hard drive in your PC and install OS3.x using WinUAE.