Looks OK - they have a landline telephone number, postal address & company number displayed on the site (click here), & the details match the corresponding domain info click here, Google maps click here (& zoom in) & Companies House info (click here & enter the co number & press Search). Apart from that, I don't know anything about them.
Before ordering, make sure to read their T&Cs click here & pay with your credit card. Regarding the latter, I think you're only covered for purchases of £100 or over though. G