I found this library : https://github.com/vfr/Reader and i tested it with a big pdf file (Very large PDF-files) so i think that's what are you searching for.
There are some interesting options so you can enable or disable some buttons or some visual effects
Edit : Using web view to load Pdf File
You can also use a web view to load the pdf file. To do that :
UIWebView *webView = [[UIWebView alloc] initWithFrame:CGRectMake(x,x,x,x)];
NSURL *targetURL = [NSURL URLWithString:@"http://developer.apple.com/iphone/library/documentation/UIKit/Reference/UIWebView_Class/UIWebView_Class.pdf"];
NSURLRequest *request = [NSURLRequest requestWithURL:targetURL];
[webView loadRequest:request];