SPS171A, JBL amp opinions?

ok i got some alpine sps171a's. (16.5cm 50wrms 250w peak)

noticed a cheap JBL amp 4x104wrms which could amp my 6x9's too (might well be scrapping these and using 2x284wrms)

heres an ebay link

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=5880094032&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

just dont know what these amps are like. will i get some decent performance from the sps's or is there a similarly priced amp which could be better? opinions please

thanks,

Rhys