Im 28 with 1yrs NCB and have just bought my 1st Supra from Jurgen on these forums.
I got a quote from Sky around the £1300 range, fully comp, agreed value, like for like on the mods, with 2 additional drivers....which I thought was great given my NCB.
I then thought I'd try Lancaster Insurance as well since my J-Spec Supra is 10yrs old and qualified for their classic car policy. I was quoted around the £800 mark for a policy with: limited mileage (6000), fully comp, agreed value, like for like on mods with 2 additional drivers. Im now insured with them. The excess is £120.
I believe their underwriters are Lloyds, but, unlike Sky you do have to tell them what your mods do, and what your estimated bhp is with the mods. Its best to phone them up rather than using their online form as it doesnt collect enough information about your car.
I would recommend either company.