Advice On Drum Pads

Hi,
Can anyone advise me on drum pads - i appear to have a drum kit with drum sizes that i cant find a matching drum pad practice set for i have the following:

Floor tom "14"

Snare "13"

Mid tom "12"

High tom "10"

Base "18"

Ride/crash symbol "14"

High hat "12"

My main question is - can i fit a smaller drum pad - say a "12" on a "10" drum?

Also if a pad is labelled a "tom" pad will it also fit a "snare" and vice versa.

Sorry if these questions are dumb but i seriously need a set of pads otherwise im going to get evicted!

Any help appreciated.

PS - Any cheap suppliers in the UK would also be helper as im poor!

Thanks.