If you’re changing the tire, wheel, and fork it might make sense to look for a comparable used bike.
A 29 tire takes 20mm more space than a 27.5 (622mm - 584mm(diameter)/ 2 (per side)). A 27.5 x 2.8 (70mm) is the same diameter as a 29 x 1.9/2.0 (50mm).
On a hardtail, it might make sense to put a plush tire in the rear for suspension and tall tire in front to get over obstacles. Maybe go 29 front only.