Bitcoin / Litecoin requires different type of mining rigs – ASIC miners.
The main disadvantage of any ASIC miner that they are designed only for mining one coin.
Shark Mining rigs are ready to mine any GPU-minable coins (Zcash, Ethereum, Monero, Bitcoin Gold and 55+ others) and the list is expanding daily (see here LINK).
GPU minable rigs are much more flexible, and you can switch to new coin any days depending on current profitability. With ASIC miner you locked in with one coin only.
Here is the most popular SharkMining rig based on 6 NVIDIA GPUs: https://sharkmining.com/us/shark-pro.html/
If you prefer to hold your mined coin in Bitcoins, you can easily exchange other cryptocurrencies (Zcash, Ethereum) to Bitcoins using any online exchange website in second with low fees (0.2%-0.5%).