In Bottles v Bladder its worth thinking about weight distribution. Raidlight Olmo 20 has two bottles up front held firm by the chest strap. The bottles counter balance the gear on your back . This helps the waist strap to ride higher reducing chaffing on the lower back. The Raidlight bottles also come with a removable straw system so you can drink without taking out the bottles. The only drawback of the Olmo is that its built so light that it won't last as long as some others.
Having said that I have stitched mine back together for next weekends Fellsman as its ideal for a 60 miler fell Ultra. Been using the Olmo for 4 years now and just can't stand the idea of binning it! (it's ramming all the kit for mountain marathons into it that has done the damage)
My fourth fellsman and I will use one pole but only for the descents to take the stress off my knees. I don,t use them for the up hills. If it's wet then they give me more stability and speed down hill. Used poles for the first time in the UTMB and would not even consider alpine running without them. They help on steep firm uphills but it's on the massive descents where they really pay off!
When buying poles you need running poles not walking poles. Running poles are a fraction of the weight and are more bendy.
I will be there. Trail shoes would be better even if it is dry. At times you will be running down very steep slopes so the extra grip will help. Some of the slopes are steep grass which can be slippery even if dry.