I don't think cams alone will cause any problems with the bottom end. Power increase is only about 15-20% with chip and that power itself does not really hurt the bottom.
Biggest load to con rods, pistons etc is when piston is at TDC between exhaust and induction cycles. Then there is nothing much above piston to slow down the piston that is going up and then changes it's direction. Realistically this phase is not affected by camshaft at all.
What will break bottom ends is high revs. Small unbalanced masses on crankshaft can be very bad, lubrication might not be sufficient to maintain bearing surface clearances. Also con rods must be able to change piston's direction faster, causing higher stresses and fatigue.
Shrick cam set is around 600€ in germany. Because they are so tame (256 degrees and 10,4 mm of lift I think) similar or bit more aggressive cams can be reground from originals. You can get set of used M42 camshafts for 10-20€ / pair and regrinding them in Finland should be around 100-150€ for cam.