A group is the best way, but as you say many are not open to low hours guys. Often the insurance is set at 100 hours, but you may be able to join and then arrange to fly with another group member to build your time until the insurance is happy.
When hiring from a club, they will often have something tucked away for solo hire and is not part of their normal training fleet. The PA28 and C152 are their work horse training fleet, and will usually be fully booked for training. There will then often be something a bit nicer, maybe a C182 or AA-5, TB10 or even an arrow, which could be available for solo hire only.
This means it will not be subject to the strict slot times of training aircraft, and usually the school is happy for you to take it away overnight.
These aircraft will usually be an extra £10-£20 an hour, but will fly much faster so if you actually want to go somewhere it would end up costing you less.