Ok, I will start by saying that flat out a conjured bow isnt as good as a deadric bow with fully upgraded fortify smithing gear/potions (achieved by getting 100 in enchanting, alchemy, and of course smithing), not to mention the enchants you can put on them. For example my fully upgraded bow hits for 580 dmg with a 36 fire dmg and 36 shock dmg enchant on it. This is also accomplished by enchanting your chosen armor with 47% bow dmg (both helms if you use circlet /fahlmer helm combo, gloves, ring, necklace is 5 pieces). Im sure that 47% (which just happens to be what my bow enchant is, yours might be higher or lower depending on your crafting proffesions) would also increase the dmg of a counjured bow, but in the end the carfted one would be better. Having said that if you are planning to go archer/conjuration which is amazing.. get your gear enchanted with both archery and conjuration so you can free cast (no mana instant summons) to get your atronachs out. This way you can put 0 points into magicka as you level. My guy is lvl 52 and has like 510 hp, 100 magicka, and 200 stam and master difficulty is easy.