Single lever shut off??? You might be refering to "ball valve" but elaborate so we can be certain everyone is talking about the same thing.
"is it common for plumbers to just quote the price and not specify what products they are using? " Very common and about as good of way as any,,,,,,,,UNLESS buyer either A. Understands plumbing and is capiable of judging material. Majority don't/can't. B. Has their knowledgable repersentive create a scope of work calling out details of material and methods. The scope is created and supplied to all bidders insuring that each is useing same parts,material and equal performance. C. Places their interest and athority 100% in the hands of a third party.
1 year warranty on material without spicific mfgr's warranty as well as labor is fair and reasonable. Most mfgr's warranties DO NOT cover labor. Think long and study hard before useing the net as substitude for A,B or C. Better to just choose a plumber based on repitation and referances then following his reccomendations.

I have a "Single lever shut off???", and have for years and years.

They work fine and promote the conscientious shutting off the hot and cold supply valves after completing the wash. Also, if one forgets to shift the lever after using the washer, it is readily apparent the next time you walk by and takes but the flick of a wrist to correct.

Google on washing machine lever water and you'll get some choices.

Here is a link that might be useful: One Model

This post was edited by saltidawg on Thu, Nov 13, 14 at 18:43