My upload is 1.1mb however my download is 9-10mb so not as lucky as you. The TV should be installed no problem on the date given , If you decide to switch I'd give notice on your TV but leave your BB and phone active with VM until Sky activate these.
Order online and get free Sky+ HD box and £25.00 M and S Voucher go through quidco and there's cashback to be had
http://www.quidco.com/sky-digital-tv-and-broadband/