You could always buy a used one, figure out for certain what you want, camp in it this summer and fall
, then sell it just before your new one is ready. You can modify what options you want right up until they start constructing yours - at least that is my understanding.
That is a variation on what I'm doing. Have a used one now to figure out what options I really want, what size I want, and what I can do without. Once I know for sure I want a new one, I'll order it, and continue to use the used one until I take delivery. These hold their value so well, and are so quickly sold, that there is very little financial risk in starting used while waiting for new.