I have had loads of units in the past ( in a different business) just a couple of hints if you have never had one before.
Council run "Enterprise units" are usually the most cost effective, but be very careful with ANY lease you sign, as you may be asked to sign a Personal Guarantee, ( even if you run a Ltd company ) what this means if you go bust ,YOU will have to keep paying the rent and rates until the lease is up ! Have a professional read the lease for you !!!
Try to get a lease on a 90 day notice where at any time you can, and the council can, give each other 90 days notice at any time.
Also check out all the costs , water rates (is it on a meter) Unit insurance costs, business rates , electrics etc etc .
Good luck , Paul.