However, those are 8th and 9th level powers. Is there anyway of doing it not so late into the endgame?
Also, each time means a level lost. Ouch.
You do realize that you can gain twenty levels inside of a few months? Even if you were going on a really slow schedule of a year a level, you could become 20th level in 19 years. If you started at 20 or so, you'd only be 39 years old (so, no age penalties).
Basically, if you're interested in immortality, you only
need to switch bodies every few decades. So, this solves both problems:
1) You'll likely have 8th and 9th level powers by the first time you need to switch bodies, and
2) You'll gain that level back* well before you need to do it again.
*Note that the way XP tables work in 3E, you gain more XP for an encounter if you're lower level than the rest of the group
and it takes less XP to gain a level when you're lower level. Over time, the XP gap actually vanishes. So the "lost" level is never truly
lost as it is
invested.