Crossbows come in a variety of styles , sizes , and price ranges , just as vert bows do . I would reccomend the simpler construction and maintenence of the Excalibur line , dollar for dollar you can't find a better design . They are as powerful as any of the compound styles , and are much easier to tune and maintain . He will probably need a cocking aid for any model much over 150# draw weight , I have one that's 180# and I grunt when I draw it .

Crossbow bolts are the same shafts as regular arrows , but the nocks are different and the bolt is considerably shorter . The longest ones I use are 20" . You can use any broadhead that you would normally use , I use Thunderheads in 100 grains . A scope is not essential if the sights on the crossbow are reasonably true , but it doesn't hurt . Both of mine came with red dot sights , which seems to be common .

Here's where you can find some to try out or buy:
Crossbow choices

Several of the major manufacturers are represented there , along with some cheapo brands if you just need something to start out with . The prices are fairly representative of pro shop prices , though slightly lower in some cases .