[TowerTalk] Screw-in guy anchors for 48' 25G installation?

[Edward Post III]

Designing my 2ndary tribander tower (large ish tribander e.g, JK Mid Tri 98lbs 16 sq ft or too big?) with 48' of 25G I now have.

Going to mount first section of 25G to small barn at 7-8', put some concrete anchors in the 25G base and put 1 or 2 sets of guys at the appropriate levels per Rohn catalog.

Question is can I get away with screw in anchors (e.g. Rohn GAS625 4' screw-in anchor (DXE web site) or the like) for this use case or must I go with concrete anchors per Rohn catalog to be safe?

2nd question, might utility pole anchors be better and if so where to source and how best to get into soil with lots of rock .. what kind of machine if any?  Are there pros who do this?

Thanks in advance

Ed W2MKM