Understand Aleksandr, was just thinking out loud, done a few myself.
Buy decent fittings, if you buy low end parts you may end up regretting it, especially if you value your sword.
Maybe worth considering having everything new, Tsuba, fuchi koshirae, menuki and seppa, it gives it that personal touch, rather than mixing the old with the new. No fit issues, which can be an headache.
I enjoyed searching for parts too, educational. It can take some time sourcing correct parts, which can be a blessing, spreads the cost out.