27.2mm x 400mm Posts

Does anybody make a 27.2mm post in lengths equal to or greater than 400mm?

I suppose shimming a 25.4 is an option but I want something strong as it’s for trials.

27.2 diameter by 410mm long Thomsons post: http://www.lhthomson.com/elite_sizes.asp

You can use the top part of a http://www.unicycle.co.nz/shop/unicycle-parts/seat-posts/KH-Adjustable-Seatpost with it, or a heavy http://www.unicycle.co.nz/shop/unicycle-parts/saddle-parts/KH-Rail-Bracket