I have a Coda Bow Diamond nx and quite like it but considering a second bow..Does anyone have an advice to give about Glasser bows or Jon Paul Bravo bows, or any bows they have found to be good for up to around ?250 (though musch less would be preferable)
something responsive for fiddling/ double stopping would be great.

I have a Jon Paul Bravo which I chose in preference to the CodaBow of which I tried at least 3 different types, including the Diamond. The Bravo is incredibly light, produces a good sound on my handmade violin and on the Gliga Gama for which it was bought.

I would think you'd find it very good for fiddling - the only thing I find my other (wooden) bow better for is playing repeated slurred semiquaver groups G - E strings and back again.

I've tried the entry level Glasser bow and it was a nice, affordable bow as a spare although you may want to consider the next one up in the range which I think is the Advanced Composite. However, out of the two, my preference is for the Codabow - particularly the Diamond SX.

I've never tried Jon Paul Bravo bows but Col Legno bows would be in your budget and may be worth a look - they are nice, responsive bows but I did find them to be very lightweight compared to other CF bows.