VAT quote query

I am self employed and usually turnover less than 25k pa - profit 8k if lucky
My clients are mainly private ( ie not businesses) so not charging them VAT suits me and them as they can't claim it back so it might lose me business have to add 17.5% to the domestic client price list

I was approached out of the blue to cater for a corporate client in March 2010 and ( just before tax year ended so knew I would be okay with the VAT thresold ) Invoiced 10k but only made 1k off it but was happy with that as its invaluable experience , a hard market to break into and something which should take years to build up a reputation as the big companies tend to dominate.

Have just been approached yesterday by the reps of a big ish company who heard good things about the March event and they have asked me to quote on a big event in December

My conundrum is that the quote will be about 40k ( maybe 8k pre tax profit - don't think thats relevant but there it is just incase)

I'm a little fish in a big pond here . I self assess at the moment - no accountant , have a 24 hour ( well 18 hours now) deadline to submit the quote if I decide to go for it

If I quote then the 40k plus the usual 25k ( on a good year quote) would JUST tip me over the VAT threshold
Can I quote and include VAT in the quote given I'm not registered yet ??? Scared about doing that but I don't see how I can quote without VAT incase I get the job and perhaps tip over the threshold

Don't want to register first thing tomorrow on the basis of a maybe quote , so any advise mucho mucho appreciated