My upload script does pretty much the same thing, with one tweak to handle newline conversion when uploading text from a Wintel box. (My ISP has CGI.pm 1.45, and I haven't had noticed any problems uploading.)

my $stripCRs = param('filetype') eq 'text';
...
while ( <$upload> ) {
    s/\r// if $stripCRs;
    print UPLOAD $_;
}
[download]

Getting a pair of radio buttons on the upload form for 'text' and 'binary' is left as an exercise.