Kenno,
Buying hardboard snooker tables wil quickly lead to disappointment.
Within a matter of months, slow shots will wander around the table, onto cushions, away from cushions.
A 6 or 7 foot slate bed will be heavy, but maybe not as heavy as you think. And if you buy new, make them installing it part of the deal.
If you're really keen on playing, I'd honestly recommend saving for a slate bed.