Sounds like it should be a great tank for whatever you go for. If you are spending that amount on a tank you would probably be best checking out what kind of fish you are planning on keeping and match the tank to that first.
Since you are going for 8ft in length something like 3ft to 4ft deep and 2-3ft high would be ideal for allot of fish. You should look at getting the tank sumped rather than running canisters on that sort of size tank as it should mean better water control and also means you can hide all your equipment. If you get a tank that is around 3-4ft deep it also means there would be plenty of room to try a cool 3D background. At that size you may wish to go for DIY but I know ND Aquatics will make a 3D background to suit any tank size. I would also opt for opti-white glass on front and sides.
No point having such a large beutiful tank if you don't get it right first time. You should aim for a factor of safety of around 5 as a minimum for a tank of that size. So if you went for 3ft tall I would suggest 15/16mm thick glass and at 4ft tall around 19mm glass.
Cost for this will be high. I would have thought with stand, sump, lighting, tank, media, heating with that sort of spec you are looking at around 3k for planted and 2.5k for something like Cichlids.
I would also suggest if you go for a really tall tank maintance will be allot harder and more time consuming.
In regards to bricks. They will be fine but getting it level and secure will be a problem in that construction. Metal framed with marine ply top would be the best way to go for that sort of size aquarium.
Also where are you placing the tank as that is allot of weight and you may well need to reinforce the floor?
Kind Regards,
Adam