I have a bit of experience with the SOHC Modular engines so I can tell you what I know. They are "good" motors when stock, but certainly not "great" until you spend a lot of money throughout the entire block to support higher rpms or an expensive supercharger or turbo setup. The physical size alone makes it difficult to fit certain packages, and it's mostly due to the OHC design. Lifting the hood on say a 94-96 Thunderbird with the SOHC 4.6L you'd think "Dang that is a huge engine" and while it might appear to take up a lot of space under the hood, it's ONLY a 4.6L.... 281 measely cubic inches. The oil fliter will likely need relocating; it was an absolute mess to change on my Tbird in even those bigger tight quarters. Exhaust manifolds are crap, and the available "shorty" headers are not an improvement, due to their tight-quarters design. These motors in stock form make squat for low end torque, and are somewhat happiest in the midrange rpms. Upgrades such as cams/heads/intake (all a bit on the pricey and somewhat limited in selection side) will only move that powerband up higher, and any significant amount of boost/juice will require forged pistons, rods, and crank. High rpms past 6K unboosted will need at least forged rods internally, and then all the other bits needed for that rpms and airflow (heads, cams, springs, etc.) You won't be able to "carb/distributer/4 wires to run" this engine and even the 4R70W trans is electronically controlled. $10k spent in just upgrading the engine itself isn't uncommon in some circles. If you plan on using the 4R70W trans the Mod motors usually came with, it won't take much more power than the stock 4.6 makes without internal upgrades and the stock torque converter is absolutely garbage.
The stock SOHC 5.4 makes just a little more torque, but not as much more as you'd expect. And it's also just a bit wider than the 4.6 already is.
Bottom line: it's your project, your money, and your time but I would hard pass on this idea unless you have plenty of Time and Money and will be content with just being able to say "Look, it's got a Mod motor in it" if/when you finish it.