Technicolor router is rubbish, could I use this one?

[#1]

http://www.ebay.co.uk/itm/Belkin-N-300-Mbps-Wireless-Router-WIFI-Access-Point-Cable-ADSL-4-Port-F5D8...

[#2]

Are you on ADSL or FTTC ?
I've not had many good experiences with the more recent Belkin stuff so you might want to do some research and read some reviews on whatever you're looking to purchase.

[#3]

FTTC. IT does support cable and ADSL and plus net will give me any PPOE details I need.

[#4]

It appears there may be a mistake in the listing as it doesn't appear to support ADSL (hence why it says it is a Cable modem).
It should be fine for your FTTC connection though but again, worth reading the reviews although the majority do seem to be positive on this router.
Your username and password  will be whatever you login into the customer portal with and @plusdsl.net on the end  i.e.  yourusername@plusdsl.net