I started my system years ago with a NAD amp and CD (302 & 502).
If you can stand their functional 'Army' looks, it could be worthwhile listening to their more recent models. - Price wise, you may be able to get some good deals from Richer Sounds as they often stock models at a very good price.
Cambridge amps have always been considered a good buy, though I cannot vouch for the personally.
Don't know much about the Sony or Pioneer kit, but Denon also had a reputation for quality budget amps.
Check out Richer Sounds for price or a BADA dealer as they should give you a good service and know the products (they don't sell washing machines).
pioneer amp a109 sells at about £100 is resonable
Try a marantz Cd5400 retails @ £150 but you might be able to find it cheaper
If matching components is important then check out the pm4400 it might push you further over budget but it's the 1st budget amp I actually rate!