I'd not bother now. Don't forget to set up the extended hire period to reduce the final value. TBH how about an interest free loan to staff - that's what my employer has chosen now - knocked back the scheme in favour of this. And you also have advantage of £1000 of cash to go and get a bike at sale or reduced price rather than RRP.
If you're concerned they'll just waltz off with the cash, then get them to buy the bike first with a credit card and then give them the loan when the show you the receipt. If you do a loan rather than the cyclescheme and you're feeling generous, you may be able to loan more than £1k without running into problems under the Consumer Credit Act highlighted by carolonabike. You'd better double check my thinking on this before you do it though!