Computer Program Written to Process Intel Hex Files - repost

I am looking for some software written to process Intel Hex Files. The software will comprise of the features outlined below. I am ideally looking for people who have experience dealing with low level files in hex or binary as the job is about manipulating files at a low level. Please provide examples of previous work where possible. There are a number of other projects also for the successful bidder assuming this job goes well. Any questions please let me know. • The software must be designed to run on Windows 7 32 bit or 64 bit. • The Software must contain a nice user friendly GUI • The software function will be as follows: o Take a standard Intel Hex format file o Convert to Regular Hex or Binary o Add two Configuration Packets of Data at the front of the data. Configuration packets will be generated by the software based on some user parameters entered into the software and also some basic Calculations on the Regular Hex Data etc. • It will be possible to save a configuration file with the user parameters and load it back in again if required. • The new Completed Hex File along with configuration packets added will be cropped to a specified size and will be saved as required. • The option must also exist for the user to encrypt the complete file before saving with XTEA Encryption using keys specified by the user. The Whole software is quite simple in reality but as mentioned it involved the manipulation of data at the byte level so experience in this is essential. To give an example WinHex will take an Intel hex File and convert it to standard Hex, shift data etc. with ease. Any questions please ask, Thanks, Stephen