sorry if the links didnt help you out with some ideas on building a portable tying station but maybe someone else will appreciate them to get ideas to make their station.
as can be seen in the links, one size doesnt seem to fit all and there are some relly creative tying stations
i have an oasis tying station that i really dont like to use so i just may look at some of the ones i do like from the links, combine the different features and make my own.
good luck in finding the one thats just right for you.