There are quite a few threads on solicitor costs before, so perhaps do a search. It's very difficult to give an estimate without further details so you would be best to ask your solicitor ( when you choose one).
As for recommendation, again there are previous recommendations if you search. You do not say which area you are in, so I assume you are in Dublin- and there are plenty of previous recommendations for Dublin.
In regard to payment, say a solicitor wants 1%, i got quoted a price from a solicitor and asked her "when" we pay her, she said she takes it out of the deposit, ie we never get a bill.
So, say i agree a house fro 200k, have 20k myself. Does the bank then loan me 182k? Ie 180k for the house & 2k for the solicitor, or do i have to come up with 20k + 2k? Is that how it works?