Are there any software defined receivers capable of receiving Regular FM broadcast band stations and displaying a waterfall of the band from 88 MHz to 107 MHz or a significant portion of that range?
Almost every SDR receiver is capable of receiving the FM broadcast band. The ones which can't are typically SDR transceivers designed for specific HF bands.
The harder part of your requirements is the waterfall of “the band … or a significant portion of that range”. The FM broadcast band is 20 MHz wide, and to display all of it straightforwardly requires delivering that entire bandwidth to the attached computer (I assume you are looking for that type as opposed to a single-box SDR).
When evaluating a receiver, look at the bandwidth (MHz) or sample rate (MSPS), and that tells you approximately how much you will be able to see ay once. (Approximately because there will be band-pass filters which have some rolloff at the edges.)
However, another option if you are not looking to demodulate any one station while you are displaying the wide-band waterfall, then you can use software which rapidly steps the receive frequency across the range to construct a composite image. The most well-known tool to do this is rtl_power, but I understand that it is a non-real-time tool (I could be wrong); I hear from comments that SDR# can do it real-time.
The HackRF is a relatively inexpensive SDR that is capable of capturing the entire FM broadcast band. It costs around $300 and can sample up to 20MHz of spectrum at a time. It can tune between 1MHz all the way up to 6GHz.
I have had good luck using a software defined radio rig that starts out using one of the European TV USB sticks. They are often sold as RTL-SDR or as DVB-T USB STICKS.
With the right software, you definitely get a waterfall display, and you can receive anything above 70-80 Mhz without any additional hardware or mods.
I use HD-SDR and the SDR# application to tune the radio and give me a waterfall video display plus audio, plus the receiver-controls. Locally Broadcast FM is so strong that even the little stubby 4 inch tall antenna that comes with the USB-Stick (RTL-SDR) will give you fine reception.
Mine has an HF upconversion board that can be switched in, that was homebrewed by my local amateur radio club, but the unmodified version will work fine with RTL-SDR software, using that board, I can tune HF and VHF. With the upconvertor, I have a more general coverage SDR solution that will tune AM broadcast bands and the Amateur HF bands.
Sample hardware: (not vouching for this amazon product, just giving you a screenshot) http://www.amazon.com/NooElec-RTL-SDR-RTL2832U-Software-Packages/dp/B008S7AVTC
Software sample: http://www.rtl-sdr.com/big-list-rtl-sdr-supported-software/
Blog post by me on the PARC Lil Pup upconvertor Plus RTL-SDR build: http://ve3wpx.blogspot.ca/2014/04/building-sdr-kit-project-lil-pup-build.html