Before any estate agent will take you seriously you'll need to know what you can borrow. You'll have to talk to a mortgage provider or two for that, or see a broker. Many estate agents do have mortgage advisers "in house" who might offer some advice but remember they are working on a commision. Speaking to a bank's adviser will normally only involve you getting advice from that banks's range only.
You have a good deposit which will help you to get a more attractive deal. But you might want some of that for your other costs you will incur. As important is your credit and employment history. All are taken into account.
Remember when you are working everything out not to overstrech yourself. Interest rate are and have been very very low for some time now. They will go up, but by how much is unknown. In the early 1990s they reached a nasty peak of 15%

although those levels now seem unlikely. Don't forget with your budgeting to allow for stamp duty, legal fees, the mortgage administration / valuation fee (often far more than the real cost of the service), any more detailed survey you might desire. Once you have the property, what costs will there be to move in? Have you allowed anything for changing carpets curtains decorations? It all adds up.