A very possible thing.
Get your prefered block builder to carve you up a block with no waterjackets with 4K bore and stroke specifications (around $5000 USD)
Get billet alloy crank, conrods, pistons. ($1000 for the crank, $1000 for the rods, $2000 for the pistons)
Custom forged head (no water jackets once again...and not pushrod, go twincam) $8000+
billet uber huge custom cams ($500+ each)
Blower or turbo (Really unsure here, blowers chew heaps of HP but turbos take a fair bit of exhaust gas to spool....) $2000+
Custom dry sump $1000 (keep all that nasty nitromethane soaked oil out of the engine as much as possible)
mechanical injectors, manifold etc $1000
probably some other stuff Ive missed but we're looking at a grand total of around $22000+ (probably more in the vecinity of $50,000 considering all the custom gear)
Horsepower capability? really don't know... run it on nitromethane at 55psi boost...and I recon youd drop below 10 secs