How can I achieve the optimal connection for using Tor as a client, in terms of bandwidth and response time, given infinite resources? Can I set up a server with very strong connection and do a VPN into it from a client machine (eg. browser on a laptop)? Could I connect to low-latency nodes only? Etc.
Short answer is no. It is possible to do so, but would very much lower the anonymous nature of your traffic. It would be best to run A relay node 24/7 to increase the amount of "fast" circuits that you connect to.
Tor itself seems to pick reasonable circuits these days.
There is no support for picking a certain set of nodes based on the properties you want, and if there was, it's unclear if that'd help.