If the AN caps end up sounding a tad too warm and or tame, then your best bet are the Vcap Odams. I upgraded two Thor preamps like yours over the years and the Odams are a great match for this unit. They are also smaller in size and fit well.
I did use the AN copper foil caps once in the Thor and changed them out in the end. Nice warmth and body for sure. In the end I found them a tad dull or dark in the upper mids and highs. Bass is also more rounded and less articulate than the Odams.
Its all about system synergy and your sonic preferences in the end. Your system and ears may prefer the warmth and slight darkness on top of the AN caps. If not, you have a great option!