Those 4 bulbs will be enough.
For the part numbers go to light producers website. Or make a search on web. search like "2x55w pll ballast" You'll find many of them.
This is i found for 80w: Philips HF-P 280 TL5/PLL EII 220-240V 50/60Hz 871150006016730
And these are for 55w: Philips HF-P 255 PLL EII 220-240V 50/60Hz 871150006062430. / Osram Quicktronic QTP-DL2X55 EAN: 4008321117960
Only important thing you should look in names is 2 55, 2 80 and pll signs.

Note: This ballasts will run both lamps at the same time. There is no option like one on and one off. You'll be able run 2 or 4 not 3 or 1.

For more, go everywhere in this forum and check this thread.
Answers about CFL, HPS, How Much Light...

Good luck with all :thumbsup:
tevfik Reviewed by tevfik on . cfl wattage guys iv been looking on ebay at cfl's and im kinda confused. allot of them seem to say 30w > 150w...or 30w same as 150w....how do you judge which one is which? i added a link to show what i mean i know its a stupid question but i cant get my head around it. wap.ebay.co.uk/Pages/ViewItem.aspx?aid=190469967508&emvAD=240x259&sv=150w%20cfl%20bulb&emvcc=0 Rating: 5