Imports are pretty safe (at least so far) mixing your own will be straightforward if a 10ml 20mg bottle of nicotine is sufficient. If it isn't it is back to the black market for your nic. Please try to find a reputable vendor and don't be tempted by sellers offering nic higher than 72mg/7.2% it can be very dangerous handling the higher percentages. At 7.2%/72mg its still not to be thrown around willy nilly, but at higher percentages it actually gets dangerous. Much like vinegar won't harm you but concentrated acetic acid might.