I am building a wood/fibreglass/acrylic tank myself. When you say liquid acrylic, do you mean acrylic resin for waterproofing? I can't remember where, but I read somewhere that acrylic resin isn't suitable as it is not 100% waterproof and that it is better to use two part epoxy instead. But check your sources on this to be sure. Have you used the garf.org website for estimations yet? It's a great tool.
Care for some DIY links?