The top three brands of crossbows are Hortons,, TenPoints/SixPoints,, Excaliburs,, your best bet would be to take your father to a proshop that carries all three and see which one he likes the best,, for me personally I like the TenPoints I fell there is no better crossbow and I have shot both them and the Excaliburs I Liked the TenPoints so much that I got my dad who is 77 one.. and he loves it, dont buy into the hooplaa about tuning your own bow and changing your own string in the field ,, ask how many have had to change a sting in the field , and ask the experts about tuning it is not as big an isshue as you will hear it made out to be, it is reccomended you have a TenPoint tuned when you have a string changed which is reccomended every 3 years.. and tenpoint has the best cocking aid and scope on the market.. with the Accudraw and accudraw 50 and their new 3X ProView scope.. go to each manufactures website and do some reserch with your father then go to a proshop that offers the crossbows your father is interested in let him handle them and shoot them ,, then you will know which one to get.. JMO