If you think you will use the hand torch, thats a good package. If you just got the machine torch only it might be cheaper and you could keep you Miller for hand cutting. There is another RS485 option for the 45xp that allows you to control the machine from the CNC controller. But its pretty expensive for what it is, it might be something you could add later.
You won't be buying a Hypertherm THC for home and hobby use. The best and also the most cost effective plasma controller and THC is LinuxCNC's Plasmac controller. We have a prebuilt table that uses it coming in Australia and the USA but it might be premature of me to suggest it as the design is incomplete. But if you could wait a little while, feel free to PM me and I'll put you in touch with our US counterparts.