These are less expensive:-
You'll only need 6 of these if you don't mind 48 instead of 49.
I've made several purchases from anykits and they are trustworthy.
You'll also need 6 x 74hc595's.
What I'd suggest you do is begin in small steps.
- Learn how to program a few LED's using Arduino's digital outs
- Learn how to control 8 LEDs using a 74HC595
- Buy a single 8 channel relay board.
- Test 8 light bulbs.
Once your comfortable controlling 8, then you'd have the option of buying more boards, or designing your own custom controller.