Need help finding correct oil pump pick up tube

I am having a hard time finding the correct oil pump pickup tube or screen for my motor. I am doing the rear sump oil pan swap i have everything besides the pickup. What length and depth of pickup tube do i need for this swap?. Will a stock 351m 400 pickup work?. I have located pick up tubes from the local auto part stores. But they are all to short and hit in the middle of the pan instead of going were they need to go. Please help i am getting frusterated and am thinking about aborting the entire project because of this set back.

What oil pan and pump??

Its a truck pan with a melling high volume oil pump rear sump.
http://www.google.com/imgres?um=1&hl=en&sa=N&biw=1280&bih=933&tbm=isch&tbnid=HIMeBLyVu-8E_M:&imgrefurl=http://www.sears.com/shc/s/t_10153_12605%3FtName%3Dengine-oil-pan-gasket.html&docid=SuuOi-NHPIUaoM&imgurl=http://c.shld.net/rpx/i/s/pi/mp/13567/6724599502p%253Fsrc%253Dhttp%25253A%25252F%25252Fwww.retailestore.com%25252FImages%25252FAutomotive%25252F41XH7z-7wZL._SL500_AA300_.jpg%2526d%253D8d15b3a2442fec71bb098bacdc18a407ca39b01d&w=315&h=315&ei=J2ZvT5KaGcLZ0QH0qYyyBg&zoom=1&iact=hc&vpx=850&vpy=177&dur=57&hovh=225&hovw=225&tx=102&ty=148&sig=114892245139392051770&page=2&tbnh=141&tbnw=141&start=20&ndsp=32&ved=1t:429,r:20,s:20
That is the same pan that i have.