Yes, I would also go to TentPole Technologies for a .433 diameter pole with a .030 wall thickness. Ask to talk to Tom.
You will need to measure:
1.> total pole length including the plastic tips
2.> Arc Height when the tent is pitched. Measure from inside (+ 1/2") and from outside by sighting across to the top of the tent. These two measurements should confirm each other.
3.> Arc WIDTH under the tent floor grommet-to-grommet
(Tom needs these dimensions to know how much to pre-curve the two middle pole sections since this stiffer pole will not bend as easily as the original pole.)
RUNNING THE CROSSING POLES INSIDE THE FLY:
1.> I decided to use the crossing pole grommets found on the corner tie-out cord to recieve the ends of the new internal poles. I removed them from the stake cords and sewed them INSIDE the fly corners, just above the carbon fiber apex and above the plastic snap hook, sewing onto the corner reinforcement patch. Use "button and carpet thread" for hand stitching
2.> Sew Velcro cable tie-wraps inside the fly ceiling at the reinforcements for the outside crossing pole straps. These will hold the fly to the interior crossing poles and prevent flapping and chafing in high winds. In NO case sew these to the unreinforced fly material.
3.> Buy a tube of silicone seam sealer (made for silnylon) at a backpacking store or online from REI. Apply it to BOTH sides of your stitching for the corner grommets and ceiling tie-wraps. Rub it well into your stitching and let dry. The next day add the 2nd application. This seam sealer seems to work better than homemade GE silicone II caulk mixed with odorless mineral spirits for this particular application. (The mineral spirits/caulk mix is for seam sealing at a 3:1 ratio of mineral spirits to caulk. DO remember to seam seal while the fly is pitched and taut. Personally I would seal both sides of the seams.)
4. Use a small pipe cutter to cut the crossing poles to fit inside the fly. Cut them in small increments and repeatedly "fit-and-try" to get the proper lenght to avoid making the poles too short. I'm cutting the same length from EACH END of the crossing pole to keep both end sections short for greater strength.
REMOVE the cut tubing sections by crushing them repeatedly to crack them lengthwise or carefully cut lengthwise with a Dremel tool disc, avoiding damage to the shock cords inside.
Keep the plastic ends and shorten the shock cord at one end if you want more tension. Re-insert the shock corded plastic end caps.
USING REMOVED CROSSING POLE SNAP HOOKS:
1.> Cut the plastic snap hooks from 4 of the crossing pole straps that you have removed by now. Use them to make pre-made guy lines for the main hoop tie-outs and center tie-outs at each end for hiking pole guys as shown in the instruction manual. The end tie-outs require more cord. Color code these end cords with permenant marker to keep them separate from the side guy lines.
Get the 4 extra LineLoc line tensioners for these guy lines from Tarptent. They will mail them to you for free since you are their customer. Use Kelty Triptease tent cord. (It has Specrta fiber core for max strength and is reflective.) Having prepared guy lines helps a lot when you need a fast set up. You will need 4 extra stakes or cut them at camp or use rocks with extra "rock cord" you bring.
2.> Cut another 2 snap hooks WITH about 4 inches of grossgrain ribbon still attatched. Insert the end of the ribbon UP through the back of the LineLoc cord tensioner found above the center end post.
Tie an overhand knot in the ribbon keeping the snap hook as tight as possible beneath the LineLoc tensioner. This is the hook for the center end vent shock cord to keep the vent open. Trim excess ribbon.
3.> For Patagonia you may want to consider using left over grossgrain ribbon from your removed crossing pole ties to make stake-out loops to sew to the hem of your fly. Two loops on each side should be plenty.
Let me know how any of these mods work for you.