I wouldn't commit to 6 months. If I went on to buy a house they showed me, sure. But I want to be able to sever ties with them if it ends up not being a good fit. I'd try to get them to agree to a month, with the option to extend if we worked well together, and with the agreement that if I bought after that month a house they'd showed me, they would still get the commission. But 6 months? No.
You can usually find MLS access for free. (Sometimes you have to register with an email and then get inundated with spam, so use a junk email address.) I think having an agent is valuable (for me) and wouldn't want to go agent-less, but if I found a house on my own and just wanted them to represent me in negotiations and the sale, I'd feel very comfortable making either a flat fee offer, or an offer where they get only a portion of the offered commission and I get the rest, since I did much of the work.